The present invention relates in general to tension-responsive detecting devices for use in carpet making machines, and more particularly to tight end detecting devices for attachment to tufting machines for sensing tight ends prior to end breakage and stopping the machine.
It is heretofore been recognized that it is desirable to provide means on tufting or carpet making machines to detect and respond to tight ends promptly and stop the machine to prevent production of seconds or defective carpeting material due to low-lines. The main cause of end breaks on a tufting machine is the occurrence of tight ends caused by yarn hanging on the back of the package or package holder. One solution to this problem is to detect the tight end and stop the tufting machine before the end breaks. If the tight end is detected quickly enough, the machine can be stopped before the end breaks. The operator can then release the end which has become tightened to or beyond a pre-determined tension level, and thereby eliminate rethreading and mending. Also, it is desirable to promptly detect a piece of yarn which becomes tight because of excess lint in the yarn tube or for some other reason causing tightening of the yarn beyond a predetermined level, to immediately stop the machine to prevent seconds or defective carpeting from being produced.
An object of the present invention is the provision of a durable and highly reliable tight end detector for tufting machines, adapted to be mounted on the tufting machine between the tube bar and the first eye board, over and through which the yarns are drawn to the tufting machine, which will detect the tight end quickly enough to permit stoppage of the machine before the end breaks, and which can be arranged in a manner which quickly indicates the area where the tight end occurs.
Another object of the present invention is the provision of a tight end detector for tufting machines as described in the preceding paragraph, which includes a switch bar assembly of rugged, generally rectangular, tubular cross sectional bar form, and which can be made in modules which may be assembled in elongated tight end detector bar assemblies of various lengths to span various widths of yarn sheets.
Yet another object of the invention is the provision of a novel tight end detector for tufting machines a described in the immediately preceding paragraphs, wherein indicating lights are associated with each module or end detector bar section providing plural indicating lights to indicate the zone where the tight end occurs by illuminating the light associated with the particular module or segment sensing the tight end, so that the operator can find the tight end quickly.
Other objects, advantages and capabilities of the present invention will become apparent from the following Detailed Description, taken in conjunction with the accompanying drawings illustrating a preferred embodiment of the invention.